Global warming has a PR problem. “Climate change is too slow a problem to solve in time,” as one expert puts it. Emissions we put out today won’t have much effect on the world for decades to come, so the issue lacks urgency.

That may be changing. Every day, we wake up to news about damage that can be directly attributed to our pumping out ever-increasing amounts of greenhouse gases into the atmosphere.

“Great Barrier Reef at terminal stage,” says one headline today. It explains how in the entire recorded history of the reef, there have been only four mass die-offs of coral: in 1998, 2002, 2016, and 2017. What’s the cause? Rising ocean temperatures caused by global warming, of course.

The good news is that there is still time to act. In a study published in Nature Climate Change, British scientists find that, if we start cutting emissions soon, we could reverse some of the worst effects of global warming.

Specifically, the researchers looked at extreme heatwaves, such as the one in India which killed more than 2,500 people in 2015 or the one in Europe which killed as many as 70,000 people in 2003. First, they calculated how often such events would occur if we did nothing to cut our emissions. Next, they considered how much emissions would need to be reduced to halve the probability of such events taking place.

Even if we don’t start cutting emissions until 2020, we can reduce the likelihood of extreme heatwaves as early as 2040, the study concludes. This is much sooner than previous predictions, which reckon that the benefits of reducing emissions do not emerge until much later in the century.

How drastic would the emissions reductions need to be to have this effect? Luckily, the goals set by the Paris climate agreement are much more aggressive than what we need to avert extreme heatwaves.

And although 2040 is a long time away, most people alive today will still be around to experience it. So although it may be too late to save the Great Barrier Reef, there is hope that action today can save countless human lives—not abstract future generations, but the people around us today.

Read next: Mass coral die-offs at the Great Barrier Reef are a sign of far worse things to come